Sam Biddle

In 1960, engineers set out to develop the technology that would convert our society into debt-crippled shopaholics. But before we all started wielding plastic, it was made out of cardboard—and now you can buy the original IBM prototype.

Despite being nothing more than a small piece of cardboard with some magnetic tape wrapped around it, Sotheby's is expecting to sell the "Prototype for Magnetic Striped Financial Transaction Card"—one of only two in existence—for upwards of $15,000. That's steep, sure, and you could probably make your own for less than a dollar, but this thing is serious techno-financial history:

The earliest trials were done on cardboard, although the acceleration of the invention meant that only two such prototypes were made before the plastic card was developed.

As [IBM engineer Jerome] Svigals explains, "IBM did the work for free and didn't even patent the machine-readable card it came up with. Rather, it offered its solution gratis to all, assuming that the more transactions conducted using machine-readable media, the more computers would be sold to process them. The strategy worked beyond anyone's dreams."